STOCHASTIC-ANALYSIS OF 3-PHASE FLOW IN HETEROGENEOUS POROUS-MEDIA .2.NUMERICAL SIMULATIONS

The first paper of this two-part series [Abdin and Kaluarachchi, this issue] developed a spectral/perturbation analysis to predict the varia bility of individual and capillary pressures of three-phase (water, oi l, and air) flow in heterogeneous porous media. The work in this manus cript is an extension of that work to validate the applicability of th e perturbation analysis and to study the stochastic behavior of three- phase flow. The input stochastic variables were soil grain size distri bution index, alpha, and log k where k is the permeability. In this wo rk a one-dimensional numerical solution was developed to solve the thr ee coupled nonlinear flow equations. The results using three different combinations of input stochastic variables showed good agreement betw een perturbation and numerical analyses over a wide range of flow cond itions. In addition, the results showed a large influence of subsurfac e heterogeneity on the predicted capillary pressure variability. In ge neral, this variability was highest with the uncorrelated ct and log k case followed by deterministic a (stochastic log k) and correlated ca ses. The results suggest that subsurface heterogeneity is important in predicting three-phase flow in heterogeneous porous media. Finally, t he results of this work can be used as a preliminary step for stochast ic analysis of three-fluid phase flow.